What in the Sam Hill?

What in (the) Sam Hill?

interrog. What has happened?; What? (An elaboration of what. Sam Hill is hell. Often with the force of an exclamation. See examples for variations.) What in the Sam Hill do you think you are doing?
See also: SAM, what
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • knock someone up
  • mallet
  • about it
  • bluh
  • bousta
  • base
  • bout it
  • areous
  • Sam Hill
  • blow-out